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revision 472 by ph10, Fri Dec 11 16:42:50 2009 UTC revision 503 by ph10, Sun Mar 7 17:35:52 2010 UTC
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1  ChangeLog for PCRE  ChangeLog for PCRE
2  ------------------  ------------------
4  Version 8.01 11-Dec-09  Version 8.02 01-Mar-2010
5  ----------------------  ------------------------
7  1.  If a pattern contained a conditional subpattern with only one branch (in  1.  The Unicode data tables have been updated to Unicode 5.2.0.
8      particular, this includes all (DEFINE) patterns), a call to pcre_study()  
9      computed the wrong minimum data length (which is of course zero for such  2.  Added the option --libs-cpp to pcre-config, but only when C++ support is
10      subpatterns).      configured.
12    3.  Updated the licensing terms in the pcregexp.pas file, as agreed with the
13        original author of that file, following a query about its status.
15    4.  On systems that do not have stdint.h (e.g. Solaris), check for and include
16        inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
18    5.  A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
19        quantifier applied to a forward-referencing subroutine call, could compile
20        incorrect code or give the error "internal error: previously-checked
21        referenced subpattern not found".
23    6.  Both MS Visual Studio and Symbian OS have problems with initializing
24        variables to point to external functions. For these systems, therefore,
25        pcre_malloc etc. are now initialized to local functions that call the
26        relevant global functions.
28    7.  There were two entries missing in the vectors called coptable and poptable
29        in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
30        I've fixed the data, and added a kludgy way of testing at compile time that
31        the lengths are correct (equal to the number of opcodes).
33    8.  Following on from 7, I added a similar kludge to check the length of the
34        eint vector in pcreposix.c.
36    9.  Error texts for pcre_compile() are held as one long string to avoid too
37        much relocation at load time. To find a text, the string is searched,
38        counting zeros. There was no check for running off the end of the string,
39        which could happen if a new error number was added without updating the
40        string.
42    10. \K gave a compile-time error if it appeared in a lookbehind assersion.
44  2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of  11. \K was not working if it appeared in an atomic group or in a group that
45        was called as a "subroutine", or in an assertion. Perl 5.11 documents that
46        \K is "not well defined" if used in an assertion. PCRE now accepts it if
47        the assertion is positive, but not if it is negative.
49    12. Change 11 fortuitously reduced the size of the stack frame used in the
50        "match()" function of pcre_exec.c by one pointer. Forthcoming
51        implementation of support for (*MARK) will need an extra pointer on the
52        stack; I have reserved it now, so that the stack frame size does not
53        decrease.
55    13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
56        item in branch that calls a recursion is a subroutine call - as in the
57        second branch in the above example - was incorrectly given the compile-
58        time error "recursive call could loop indefinitely" because pcre_compile()
59        was not correctly checking the subroutine for matching a non-empty string.
62    Version 8.01 19-Jan-2010
63    ------------------------
65    1.  If a pattern contained a conditional subpattern with only one branch (in
66        particular, this includes all (*DEFINE) patterns), a call to pcre_study()
67        computed the wrong minimum data length (which is of course zero for such
68        subpatterns). This could cause incorrect "no match" results.
70    2.  For patterns such as (?i)a(?-i)b|c where an option setting at the start of
71      the pattern is reset in the first branch, pcre_compile() failed with      the pattern is reset in the first branch, pcre_compile() failed with
72      "internal error: code overflow at offset...". This happened only when      "internal error: code overflow at offset...". This happened only when
73      the reset was to the original external option setting. (An optimization      the reset was to the original external option setting. (An optimization
74      abstracts leading options settings into an external setting, which was the      abstracts leading options settings into an external setting, which was the
75      cause of this.)      cause of this.)
77    3.  A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
78        of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
79        assertion pattern did not match (meaning that the assertion was true), it
80        was incorrectly treated as false if the SKIP had been reached during the
81        matching. This also applied to assertions used as conditions.
83    4.  If an item that is not supported by pcre_dfa_exec() was encountered in an
84        assertion subpattern, including such a pattern used as a condition,
85        unpredictable results occurred, instead of the error return
88    5.  The C++ GlobalReplace function was not working like Perl for the special
89        situation when an empty string is matched. It now does the fancy magic
90        stuff that is necessary.
92    6.  In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
93        removed. (These were left over from very, very early versions of PCRE.)
95    7.  Some cosmetic changes to the code to make life easier when compiling it
96        as part of something else:
98        (a) Change DEBUG to PCRE_DEBUG.
100        (b) In pcre_compile(), rename the member of the "branch_chain" structure
101            called "current" as "current_branch", to prevent a collision with the
102            Linux macro when compiled as a kernel module.
104        (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
105            prevent a collision with the Linux macro when compiled as a kernel
106            module.
108    8.  In pcre_compile() there are some checks for integer overflows that used to
109        cast potentially large values to (double). This has been changed to that
110        when building, a check for int64_t is made, and if it is found, it is used
111        instead, thus avoiding the use of floating point arithmetic. (There is no
112        other use of FP in PCRE.) If int64_t is not found, the fallback is to
113        double.
115    9.  Added two casts to avoid signed/unsigned warnings from VS Studio Express
116        2005 (difference between two addresses compared to an unsigned value).
118    10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
119        custom one, because of the following reported problem in Windows:
121          - libbz2 uses the Pascal calling convention (WINAPI) for the functions
122              under Win32.
123          - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
124              therefore missing the function definition.
125          - The compiler thus generates a "C" signature for the test function.
126          - The linker fails to find the "C" function.
127          - PCRE fails to configure if asked to do so against libbz2.
129    11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
130        messages were output:
132          Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
133          rerunning libtoolize, to keep the correct libtool macros in-tree.
134          Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
136        I have done both of these things.
138    12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
139        most of the time, it *can* run out if it is given a pattern that contains a
140        runaway infinite recursion. I updated the discussion in the pcrestack man
141        page.
143    13. Now that we have gone to the x.xx style of version numbers, the minor
144        version may start with zero. Using 08 or 09 is a bad idea because users
145        might check the value of PCRE_MINOR in their code, and 08 or 09 may be
146        interpreted as invalid octal numbers. I've updated the previous comment in
147        configure.ac, and also added a check that gives an error if 08 or 09 are
148        used.
150    14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
151        causing partial matching to fail when the end of the subject matched \W
152        in a UTF-8 pattern where \W was quantified with a minimum of 3.
154    15. There were some discrepancies between the declarations in pcre_internal.h
155        of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
156        their definitions. The declarations used "const uschar *" and the
157        definitions used USPTR. Even though USPTR is normally defined as "const
158        unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
159        reported that: "This difference in casting confuses some C++ compilers, for
160        example, SunCC recognizes above declarations as different functions and
161        generates broken code for hbpcre." I have changed the declarations to use
162        USPTR.
164    16. GNU libtool is named differently on some systems. The autogen.sh script now
165        tries several variants such as glibtoolize (MacOSX) and libtoolize1x
166        (FreeBSD).
168    17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
169        (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
170        comment: "Figure out how to create a longlong from a string: strtoll and
171        equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
172        instance, but it only takes 2 args instead of 3!"
174    18. A subtle bug concerned with back references has been fixed by a change of
175        specification, with a corresponding code fix. A pattern such as
176        ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
177        refers, was giving matches when it shouldn't. For example, xa=xaaa would
178        match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
179        same bug. Such groups have to be quantified to be useful, or contained
180        inside another quantified group. (If there's no repetition, the reference
181        can never match.) The problem arises because, having left the group and
182        moved on to the rest of the pattern, a later failure that backtracks into
183        the group uses the captured value from the final iteration of the group
184        rather than the correct earlier one. I have fixed this in PCRE by forcing
185        any group that contains a reference to itself to be an atomic group; that
186        is, there cannot be any backtracking into it once it has completed. This is
187        similar to recursive and subroutine calls.
190  Version 8.00 19-Oct-09  Version 8.00 19-Oct-09
191  ----------------------  ----------------------

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